Cornered and raging, Trump begins his coverup. Here’s how Democrats can respond.

President Trump has forced out his attorney general and replaced him with a loyalist who will now oversee special counsel Robert S. Mueller III’s investigation. Speculation is rampant: Will the new acting attorney general fire Mueller? Constrain his investigation? Block Mueller’s findings from going public?

We don’t know whether Matthew Whitaker, Trump’s replacement for Jeff Sessions, will go through with these things. But here’s something we can conclude right now: Trump surely picked Whitaker, Sessions’s chief of staff, expressly to put him in the position of being able to do any and all of them.

Unlike Sessions, who recused himself from the probe, Whitaker will oversee it, whereas before, that had fallen to Deputy Attorney General Rod J. Rosenstein. Whitaker can theoretically fire Mueller by invoking some rationale that fulfills the relevant regulations’ requirement for “cause,” or he can revoke those regulations. Or he can severely limit the scope of the investigation, or starve it of funds.

Ask yourself: What would this look like if Republicans had held the House? We would be concluding that Trump is taking steps to close down or limit the probe, or keep its findings covered up, in the full knowledge that congressional Republicans will let him get away with it. Which is why it’s a good thing that Democrats did capture the House.

At his news conference on Wednesday in the wake of the Democratic victory, Trump raged over the investigation. He said that if House Democrats investigate his administration — an activity known as congressional oversight — that the White House can retaliate by investigating Democrats. Trump vowed a “warlike posture.” This lays the groundwork to dramatically resist whatever Democrats do in response to Trump’s moves against the Mueller probe.

So what can Democrats do in these scenarios, once they’re in the majority? Here’s a rundown:

House Democrats can investigate the firing of Sessions. The question of whether Trump fired Sessions or whether Sessions merely resigned is critical. If Trump fired Sessions, it might not be legit that Trump replaced him with an acting attorney general (Whitaker) who didn’t require Senate confirmation (which Trump may have wanted to do to insulate the replacement from questioning from senators about his intention toward the Mueller probe). Mueller could conceivably challenge the appointment in court if Whitaker does try to shut down or severely constrain the probe.

Though the White House claims Sessions resigned at Trump’s “request,” it seems obvious that Trump did fire him. The Post reports that Sessions thought staying would protect “the investigation’s integrity,” which would leave the country “better served,” as its findings will be “more credible to the American public.” So House Democrats can try to investigate the circumstances leading up to Sessions’s “resignation,” to determine whether Sessions did resist it and was fired.

“The rationale would be that they were investigating to determine whether Sessions was fired as part of a conspiracy to obstruct justice,” Josh Chafetz, a professor at Cornell Law School, told me. “This could entail requests for documents and witness testimony.”

Subpoena Sessions himself. House Democrats can try to question Sessions himself, both about the circumstances surrounding his firing and, more broadly, about private meetings in which Trump raged at Sessions for failing to protect him from the investigation. Sessions would likely assert executive privilege regarding his conversations with Trump.

But Democrats have recourse. They can “haul Sessions in and make him refuse to answer questions live, on TV,” Chafetz told me. “Then, after some arguing back and forth, if Democrats decide that the assertion of privilege is improper, they can hold him in contempt.” Whether that would do much is anybody’s guess, but at least the spectacle of Sessions refusing to say whether Trump forced him out and why would be dramatized for the country.

Subpoena Mueller’s findings. Under the regulations governing the special counsel, he is to provide a “confidential” report explaining his conclusions to the person overseeing the probe — who would have been Rosenstein but now will be Whitaker. It is Whitaker who is then supposed to provide a report to the bipartisan leaders of the House and Senate judiciary committees, which gives him a great deal of discretion to decide how much to put in that report.

Whitaker could theoretically report little to nothing, in effect covering up what Mueller learned. “Democrats could subpoena Mueller’s findings,” Chafetz tells me. “But expect the White House to put up a fight in response to the subpoena.” Other legal experts think that if the White House defied such a subpoena, the courts would rule against them, meaning Congress would get Mueller’s findings.

As Chafetz has written elsewhere, one key thing Democrats must think hard about is how to use such proceedings to inform the public about what’s happening, both for political and substantive reasons.

Impeach the acting attorney general. This is a far-fetched scenario, but it’s not an impossibility. As it is, Whitaker has publicly opined that Mueller has gone too far in probing Trump’s finances and has openly suggested that one option is to de-fund the investigation. On these grounds, Democrats have called for his recusal.

Here an irony kicks in. A handful of House Republicans loyal to Trump tried to impeach Rosenstein earlier this year on grounds so specious that even many Republicans, including the leadership, rejected it. It’s hard to say what circumstances might justify such a move against Whitaker, if any, but if he shuts down the Mueller probe without good cause, that might be seen as extremely serious misconduct — far more serious than what Republicans alleged against Rosenstein.

Jonathan Adler, a law professor at Case Western Reserve University, points out that there are other forms of misconduct Whitaker could commit. Whether or not his public opinions merit recusal, he should still solicit a Justice Department ethics opinion on whether he should oversee the probe. “Rosenstein did this, and some Republicans still called for his impeachment,” Adler notes. “If Whitaker fails to take the same prudent step, it would be inexcusable.”

It seems obvious that once Democrats take over the House, we are headed for a major escalation in hostilities. Trump is already testing to see what he can get away with, so it’s good that leading Democrats just responded with a letter calling on Republicans to hold emergency hearings on Trump’s move, arguing that the appointment of Whitaker is precipitating a “constitutional crisis.” Republicans will shrug, but this suggests Democrats recognize the gravity of the moment and are organizing to respond accordingly.